Automatic tension control systems for oil well drill lines



J E BOWDEN 5,359

AUTOMATIC TENSION CONTROL SYSTEMS FOR OIL WELL DRILL LINES Aug. 9, 1966 6 Sheets-Sheet 1 Filed June 7. 1962 a llllllllllilipr? tamlnllllllniwm INVENTOR J 5 BOWDEN ATTORNEY g- 1966 J E BOWDEN 3,265,359

AUTOMATIC TENSION CONTROL SYSTEMS FOR OIL WELL DRILLTLINES v Filed June 7, 1962 e ShetS-Shet 2 FIG. 2

INVENTOR BYW ATTORNEY .15 BOWIDE'N Aug. 9, 1966 J E BOWDEN 3,265,359

AUTOMATIC TENSION CONTROL SYSTEMS FOR OIL WELL DRILL LINES Filed June 7, 1962 6 Sheets-Sheet 5 INVENTOR .1 E. BOWDEN [q oogoooo ATTORNEY 26 BYWQZM Aug. 9, 1966 J E BOWDEN AUTOMATIC 'TENSION CONTROL SYSTEMS FOR OIL WELL DRILL LINES 6 Sheets-Sheet 4 Filed June '7, 1962 v INVENTOR JE. BOWDEN ATTORNEY 5&3 mmkom x3 Aug. 9, 1966 J E BOWDEN 3,265,359

AUTOMATIC TENSION CONTROL SYSTEMS FOR OIL WELL DRILL LINES Filed June 7. 1962 a Sheets-Sheet b FIG. 8

FIG 9 INVENTOR J E BOWDEN ATTORNEY IOI Aug. 9, 1966 J E BOWDEN 3,255,359

" AUTOMATIC TENSION CONTROL SYSTEMS FOR ,oIL WELL DRILL LINES Filed June- 7, 1962 a Sheets-Sheet e vm as Q" SN m S m N (O v S INVENTOR J. E. Bowden United States Patent 0 3,265,359 AUTOMATIU TENSIGN QGN'IRGL SYSTELWE FUR GIL WELL DRILL LINES .I. E. Bowden, 503 Mesa Drive, Hobbs, N. Mex. Filed .lune 7, I962, Ser. No. 263,684 11 Claims. (*Ji. 254-173) This application is a continuaticn-in-part of my application, Serial No. 668,230, filed June 26, 1957, now abandoned.

The invention relates particularly to automatic well drilling control systems for regulating tension in a drill line as successively deeper subsurface formations are penetrated.

Accordingly, therefore, among my objects, I aim to teach an ingenious automatic control system for continuously controlling the tension in a drill line.

Another object of this invention is to disclose a means for automatically maintaining constant drilling weight on a drilling bit in order to enhance the bit efiiciency as well as the efflciency of the entire drilling operation.

Another object of the invention is to disclose a method of oil well drilling in which the location of oil, gas, mineral and water formations may be more accurately determined by virtue of the constant drilling pressure which is maintained on the drill bit.

Another object of this invention is to provide a compact portable drilling control system which may be easily attached to any conventional rotary oil rig.

Another object of this invention is to disclose a new functional relationship between the hoist drum or spool, and the friction brake mechanism of the oil well drilling apparatus.

Another object of the invention is to each a method of accurately sensing the amount of rotation of the hoist drum which occurs when the top end of a drill string is lowered.

Still further objects of this invention are to disclose means for generating a mechanical signal proportional to I the hoist drum shaft movement, and effecting a resetting of friction brake bands or mechanism in response thereto; to provide a novel construction wherein the said new functional relationship between the hoist drum or spool is accomplished at minimum expense both with respect to initial and operational costs and which may be carried out very simply and advantageously through the coaction of a pulley device or equivalent and with minimum power as from a side or end wall of the hoist drum or spool; to effect this last-mentioned object by the said coacting pulley device and drum Wall in association with gearing having planetary or differential action; to carry out the invention either by way of novel pneumatic, hydraulic, mechanical or electrical apparatus or with parts composed of any combination of pneumatic, hydraulic, mechanical or electrical apparatus or otherwise, and particularly with respect to controlling the tension on the friction brake mechanism of a conventional hoist drum, and to disclose a novel system including planetary type gearing or differential coacting with a control and well drilling friction brake system.

With the foregoing and other objects in View, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto:

FIGURE 1 illustrates a preferred embodiment of the invention in which compressed air or gas is used in conjunction with a pressurized fluid and a diaphragm tension sensor to regulate the drill line tension;

FIGURE 2 shows a view of a typical installation using the system of FIGURE 1, and indicates the method of connecting the diaphragm tension sensor to the dead line;

'ice

FIGURE 3 shows a front view of a diaphragm tension sensor;

FIGURE 4 shows a sectional view of the sensor of FIGURE 3, taken along the lines 4-4;

FIGURE 5 shows a view in section of the normally open spring biased clutch used in practising the invention;

FIGURE 6 comprises a partial section view of the clutch shown in FIGURE 5 taken along the line 6--6;

FIGURE 7 shows a preferred embodiment of the invention in which pressurized fluid is used in conjunction with dynamo electric equipment and a diaphragm tension sensor to regulate the drill line tension;

FIGURE 7A is a diagrammatic view illustrating a flexible shaft drive between the friction wheel and its worm in lieu of the selsyn arrangement of FIGURE 7;

FIGURE 8 is a plan view of the planetary gear assembly depicted in FIGURE 7;

FIGURE 9 is a sectional view taken along the line 99 of FIGURE 8;

FIGURE 10 shows a view of a typical installation employing the embodiment of the invention illustrated in FIGURE 7 to FIGURE 9; and

FIGURE 11 illustrates a further installation according to the invention which is primarily operable by compressed air or other pressure fluid.

Turning now to the drawings, and more particularly to FIGURE 1, the numeral 1 indicates generally one of the preferred embodiments of the invention in which compressed air or gas is used in conjunction with a pressurized fluid to regulate the tension in the drilling line. More particularly, compressed air or gas from a conventional supply tank is supplied to the system, via the control valve 2 shown in the left-hand portion of the drawing. The valve 2 may comprise any suitable manually operable ON-OFF type valve of conventional design.

A portion of the gas flowing through the valve 2 is forced to traverse a combined filter-regulator unit 3, which effectively eliminates any foreign particles or impurities entrained within the moving gas, and reduces the pressure to any predetermined value. The unit 3 is of conventional design, and the details thereof form no part of the present invention.

The filtered gas emerging from the unit 3 passes through a constricted portion or orifice 4 located in the output conduit leading from the regulator, and is throttled to the atmosphere through the nozzle 5. The rate at which the pressurized gas is allowed to escape to the atmosphere is controlled by a pivotally mounted flapper 6a which accurately reflects variations in the drilling line tension, in a manner to be explained more fully later in this specification. The flapper 6a exhibits a degree of sensitivity which is controlled by means of a manually operable calibrating element 66.

The incident pressure existing between the orifice 4 and the nozzle 5 is applied to a spring biased diaphragm valve which is indicated generally by the numeral 8. The valve 8 includes a valve stem 8a which is secured to and directly energized by the fluctuations of a pressure sensitive diaphragm disc located within the valve 8. The valve also includes a spring 812 which normally biases the valve 8 to closed position, and prevents any flow theret-hrough. It will now be evident that when the pressure between the orifice 4 and nozzle 5 is sufficiently high, the diaphragm within valve 8 is able to overcome the force of spring 815 and depress the valve stem 8 in order to unseat the head of the valve from its normally a closed position.

conduit 9 conveys this portion of the compressed gas to an air-actuated spring biased normally open clutch indicated generally by the reference numeral 14 The structural configuration of the air actuated clutch 10 is illustrated most clearly in the sectional view which is provided in FIGURE 5.

For present purposes in describing the system shown in FIGURE 1, it is suflicient to point out that the clutch It) acts to selectively engage a hoist drum to the planetary gear assembly 11 which is shown diagrammatically in an exploded view to the left of the clutch and further in FIGURES 5 and 6.

This planetary gear assembly includes a gear 110 which receives torque from a worm 11b. A pinion gear 110 is keyed or otherwise securely aflixed to the gear 110 for concentric rotation therewith. An internal sun gear 11d is shown slightly to. the right of the combined gear and pinion structure, along with a plurality of small planetary gears 11c which mesh simultaneously with the outer periphery of the pinion 11c as well as the inner periphery of the sun gear lid. The plan view of the planetary gear assembly 11 and its associated lever system is shown most clearly in FIGURE 6, and will be referred to again in connection with the detailed description of structure illustrated therein.

Turning now to the method by which torque is supplied to planetary gear assembly 11, pressurized fluid,

' such as oil or conventional hydraulic fluid enters the system through a conventional check valve 12 shown in the left-hand portion of the drawing. When the normally closed diaphragm valve 8 is forced to open by the pressure which is sampled between the orifice 4 and the nozzle, 5 the pressurized input fluid passes through the valve 8 to the downstream conduit, and traverses a conventional speed control valve 13. The fluid emerging from valve 13 is applied directly to a fluid motor 14 which supplies the input torque for the planetary gear assembly to the worm 11b. The motor 14 may comprise any suitable type of commercially available fluid driven device, anddoes not form a part of the present invention. The

. fluid emerging from the motor 14 is conveyed back to a sump or reservoir, via fluid return conduit .15, in the conventional manner.

Turning now to the description of the manner in which the pressure of the compressed air or gas in the system is modulated by the drill line tension, the reference numeral 16 is used in the upper right hand corner of FIGURE 1 to designate generally a diaphargm tension sensor. The sensor 16 is illustrated in detail in the sectional view provided in FIGURE 4 of the drawings. Essentially, the sensor comprises a fluid-filled flexible walled container adapted to supply a value of pressure which is governed by the relative tautness of a cable or drill line stretched therethrough.

Thus, in FIGURE 4, the sensor includes a frame 17 provided with a pivotally mounted upper spool 18 on the upper portion thereof. On the lower portion, a lower spool cam 19a is pivotally secured. An elongated operating handle 1% is integrally secured to the spool cam 19a, and extends longitudinally upward therefrom. A dowel 19c is removably positioned within a mating axial recess within the cam 19a, to assist in maintaining the handle and cam in the desired position.

The portion of the drill line which passes between the upper spool and the lower spool cam engages a conta t point center 20 which is secured directly to a pressure plate 21 and associated flexible diaphragm disc 22. The outer periphery of the diaphragm disc 22 is tightly secured to the back plate 23 by means of suitable bolts in order to form a fluid-tight chamber. It will be evident that any increase in the tautness in the drill line located between the upper and lower spools must necessarily cause the diaphragm disc to deflect inwardly, and increase the pressure of the fluid entrapped within the diaphragm chamber and conduit 24.

Continuing with the detailed description of FIGURE 1, the application of the modulated pressure output of the diaphragm sensor unit will now be explained. In FIG- URE 1, it will be observed that the conduit 24 which emerges from the tension sensor is connected directly to the fixed end of a conventional Bourdon pressure tube 24a. The tube 24a may comprise a component of a commercially available unit such as Fisher Wizard, or similar device, which is used as a controller sensitive to variation in drill line tension. Increases in the pressure of the fluid within the tube 24a effect a discernible straightening therein, and displaces the pivoted flapper 6a with respect to the nozzle 5. From this discussion it will be appreciated that the air escape through nozzle 5, and the position of the diaphragm valve 8 are both controlled and influenced by the tension in the drill line which is measured by the sensor 16. This, in turn, controls the periods during which fluid motor 14 is actuated by the compressed fluid which is allowed to enter the system through the check valve 12.

The effect of driving the fluid motor 14, and hence the planetary gear assembly 11, is appreciated most readily by inspection of the structure depicted in FIG- URE 6 of the drawings. Specifically, the numeral 25 has been used in FIGURE 6 to indicate generally a braking means or mechanism for drum 28b and particularly its lever system which is actuated by means of the planetary gear assembly 11. A slotted lever 25a is pivotally secured at one end to the radial end surface of the internal sun gear 11a. The opposite end of the lever 25a is pivotally secured to a lever 25b which is adapted to oscillate about a fixed pivot pin 26.

The lever 25b is mounted to actuate a hoist drum brake lever 250 provided with a suitable counterweight 27 suspended from the outermost extremity thereof. The counterweight 27 assists the brake system. in restraining the hoist drum from the tendency to rotate which is caused by the pull of the drill line.

Turning momentarily to FIGURE 5, to complete the necessary description of the individual components employed in FIGURE 1, the numeral 10 indicates generally a sectional view of a normally open spring-biased clutch which is operated by the compressed air conveyed through conduit 9. To the left in FIGURE 1, the component elements of the planetary gear assembly 11 are clearly illustrated. Thus, the gear 11a with associated integral pinion 11c is shown mounted for concentric rotation With the drumspool 2811' and drum shaft 281). It will be appreciated that the drum shaft 28b is journaled between suitable support members 29. The sun gear 11d and the internally disposed planetary gears 11c are shown in operative relationship. It will be observed that each of the planetary gears is rotatably journaled upon a spindle 30. Clutch 10 has a plate 10d mounted to rotate in its support 29 and on drum shaft 281). The spindle 30, in each case, is properly secured at one end to a flange 30' of the clutch plate 10d, for reasons which will be apparent as the specification proceeds.

The clutch 10 includes an airtight casing 10a disposed to permit rotation of the drumshaft 28b therein. Within the casing 100, there is provided an axially movable clutch plate 10b. The plate 10b is biased to its indicated position by means of the coiled compression spring 10c;

The plate 10b is keyed to shaft 28b for concentric rotation therewith. Somewhat to the left of the clutch plate 10b, and normally separated by a discernible air gap therefrom, there is provided a second clutch plate NM. The clutch plates 10b and 10d are each provided with suitable serrations or the like to provide a positive locking engagement therebetween. In operation, the application of compressed air to the clutch through conduit 9 causes the spring biased clutch plate 10b to move axially into engagement with the clutch plate 10d.

Turning to the sequence of operations accomplished by the system of FIGURE 1, as the drill bit penetrates successively deeper formations, the tension on the drilling line increases. It Will be appreciated that air pressure supplied via control valve 2 and conduit 9 has engaged the normally open clutch 10. The diaphragm sensor 16 samples the increasing tension in the dead line, and produces a higher fluid pressure within the conduit 24 in response thereto. This increased pressure deflects the Bourdon tube 24a which, in turn, actuates the pivoted flapper 6a and halts the air escape through the nozzle 5. The resulting increase in the pressure supplied the diaphragm valve 8 provides suflicient force to overcome the biasing spring 8b. This causes the valve to unseat and permit flow. At this point, the pressurized fluid which enters the system at check valve 12 is permitted to energize the fluid motor 14 and supply torque to the planetary gear assembly 11.

The application of torque to the gear 11a and pinion 110 causes them to turn freely on the drum shaft 28b. Thus, in turn, causes the associated planetary gears each to revolve about its individual spindle 30, as seen most clearly in FIGURE 5. However, since the planetary spindles 30 are held almost motionless by the engagement of the clutch 10, the rotation of the planetaries on such relatively stationary spindles causes the internally toothed ring gear lid to rotate slightly in the clockwise direction, as indicated by the arrow in FIGURE 6.

As a result of this clockwise deflection, the lever a is raised slightly, effecting a corresponding elevation in the hoist drum brake lever 250. The elevation thus effected reduces or partially releases the tension in the hoist drum friction brake bands, and allows the hoist drum to rotate slightly. The inherent tension in the drilling cable then turns the hoist drum through a given arc, and pulls a quantity of line from the drum spool causing rotation of the spool to allow the drill pipe string to lower, and transfers some of the suspended weight supported by the derrick to the drill bit.

When the drum rotates in this manner, the planetary spindles are each caused to rotate counterclockwise. During this interval, the pinion gear 110 is either practically stationary or moving much more slowly than the individual planetary gears. This causes the ring gear 11d to rotate counterclockwise, and relieves the upward force previously exerted upon the lever 25a. The release of lever 25a then causes the friction brake bands to reengage. Thus, by using compressed fluid as well as compressed gas equipment in combination with a diaphragm sensor unit, the tension of the drilling line is automatically adjusted during continuous drilling operations.

Continuing now with the detailed description of the remainder of the invention, and turning to FIGURE 7 for the combined electrohydraulic embodiment thereof, the numeral 31, in the upper left-hand corner of the drawing, is used to designate a conventional ON-OFF contrdl switch. Closure of the switch 31 permits input electrical power to energize solenoid valve 32. In addition, current flows through conductor 33 to electric motor 34, and returns to the mains via contact Z, the movable pole in pressure sensitive switch 35, and conductor 36, as shown.

The electric motor 34 provides driving torque to a conventional fluid pump 37 shown directly therebeneath. The pumping action of the unit 37 draws hydraulic fluid from a fluid supply tank 38, and causes it to unseat and flow through a conventional check valve 39. From valve 39 the pressurized fluid is applied to the interior of a spring biased cylinder assembly 40. The assembly 40 includes a fixed cylinder casing 40a, an axially movable piston 40b, and tensile biasing spring 41.

The piston 40b is connected to actuate a lever 42 which is pivotally mounted by means of a suitable pivot base 43. The lever 42 supports a friction Wheel 44 at the upper extremity thereof. Rotation of the friction wheel 44 causes simultaneous rotation of the rotor of a directly coupled selsyn unit 45. Thus, when the pump 37 is energized by motor 34, pressurized fluid from tank 38 enters the cylinder casing 40a, displaces the piston 40b to the right, and causes the friction wheel 44 to engage the hoist drum spool 28a. Upon the attainment of a predetermined pressure value, the movable pole in the pressure sensitive switch 35 is caused to disengage contact Z and touch the contact Y shown immediately thereabove.

As successive layers of formation are penetrated by the drill, and the tension of the drill line sampledby the sensor 16 increases, the pressure of fluid entrapped within the unit 16 and conduit 24 experiences a corresponding increase.

This increased value in the pressure tends to straighten and deflect the Bourdon tube 24a. The resulting deflection of tube 24a closes the contacts of a conventional solenoid switch 46. The Bourdon tube 240 and switch 46 may comprise components of any suitable commercially available unit, which graphically records the variation in drill line tension, as time elapses. The closure of switch 46 permits electric current to traverse the switch, flow through the control rheostat 47 and enter the 'hoist drum brake lifting motor 48. From the motor 48 the current completes the circuit by traversing contact Y and the associated movable pole in switch 35 back to the mains.

The application of power to the motor 48 causes it to deliver torque to the planetary gear assembly 49, shown in semi-exploded view to the left of the drawing. The assembly is perhaps shown most clearly in the plan view provided in FIGURE 8. The gear system is there seen to include a worm 49a which mates with an annular external gear 4%. The gear 491) is provided with teeth on both the inner and outer peripheral surfaces thereof. A pinion gear 490 is concentrically journaled within the external gear 4%, and is maintained in gearing engagement therewith by means of a plurality of planetary gears 49d. Each of the individual planetary gears 49d is journaled upon a suitable spindle 50. The ends of the respective spindles are secured in an annular flange 51 which is secured to and rotates concentrically with the brake ever lifting spool 52. Y

Rotation of the worm 49a by motor 48 causes the external gear 49b to drive the plural planetary gears 49d, and causes them to roll over the periphery of the pinion 490. This, of course, causes the spindles 50 and associted flange 51 to rotate correspondingly about the axis of the pinion 490. The rotational movement of the spool 52 thus eflected forces it to wind up a quantity of the wire line 53 which is wound thereupon. The wire line shown in FIGURE 7 and FIGURE 10 will be seen to pass over sheaves 54a and 54b and terminate in the upper portion of a hoist drum brake lever 55 which is used to control the degree of engagement of the friction brake assembly 56.

When the wire line 53 is rewound upon the spool 52,

the hoist drum brake lever 55 is actuated to lessen the degree of restraint imposed by the friction bands 57. As a result, the inherent tension in the drill line causes the drum to rotate slightly. This rotation in turn rotates the friction wheel 44, and causes the selsyn unit 45 to produce an output electrical signal. The signal thus generated is transmitted over the conductors 59 to the selsyn unit 45b. Rotation of the selsyn unit 45b provides input torque to a worm and gear assembly 60. The torque received from unit 45b is transferred via worm 60a and gear 60b to a shaft 61 which is keyed to gear 60b. Rotation of the shaft 61 efiects a corresponding rotation of the pinion 49c which is aflixed to the opposite end of the shaft. This causes the individual planetary gears 49d to rotate and walk around the gear 4%, and causes the spindles 50 and flange 51 to move through the corresponding arc. During this interval, flange 51 similarly displaces the spool 52 and causes the wire line 53 to unwind from the periphery of the spool. The resulting decrease in the relative tautness in the wire line permits brake lever 55 to re-engage the friction bands 57 and halt rotation of drum 28a.

The appearance of a typical installation using the present embodiment of the invention is illustrated in FIG- URE of the drawings. There, the console 62, which is positioned on the floor of a conventional derrick, may enclose the brake lifting spool unit, and the hydraulic system for energizing the cylinder assembly 40. The con sole 62 is fabricated of metal in order to provide an enclosure which is both explosion-proof and gas-proof. It will be appreciated, in this connection, that the console 62 is portable in order to permit the use of the invention at any of several drilling installations.

The console unit houses a convention-a1 recorder, such as the Bristol Free Vane Recorder, which provides a graphical record of the variations in drill line tension. The appearance of the circular-typemoving chart within such a recorder is clearly illustrated in the drawing. The portable console 62 also houses the control r'heostat 47, which is used to control the rotational speed of the hoist drum brake lifting unit, as explained in detail in connection with the electrohydraulic embodiment shown in FIG- URE 7 of the drawings. The rheostat 47 may include a suitable selector switch provided with convenient graduation for expediting the selection of different speeds.

In FIGURE 10 the housing 63 in the center of the derrick encloses the hoisting unit, and the drilling line 58 is seen extending upwardly therefrom. The pivoted lever 42, which supports the friction wheel 44, is shown directly below the floor of the derrick.

It will be appreciated that the complete cycle for periodically effecting a controlled diminution in the braking eifort exerted on the hoist drum has now been described. By using a combined electrohydraulie system in conjunction with a diaphragm sensor unit, the automatic tensioning of the drill line during penetration of successively deeper strata is efliciently and economically accomplished.

In FIGURE 7A is illustrated a flexible drive shaft connection, generally indicated at 70, between the friction wheel 44 and the worm 60a which may be used in lieu of the selsyn units 45 and 45b and the conductors 59 of FIGURE 7. This flexible shaft connection 70 may be of the conventional speedometer shaft type used on automobiles and comprises a flexible shaft 71 housed in a close fitting flexible housing 72. One end of the shaft 71 is connected in the conventional manner to the shaft of the friction wheel 44, as indicated at 73, and the other end of the shaft 71 is connected in a conventional manner to the shaft of the worm 60a, as indicated at 74.

The rotation of the friction wheel 44, caused by the rotation of the drum 28a, is imparted to the shaft 71 which, in turn, rotates the worm 60a.

The shaft 71 and housing 72 could be of any desired diameter, for example, the shaft 71 could have an outside diameter of three-eighths inch and the housing 72 an inside diameter of seven-sixteenths inch, and an outside circumference of three-fourths inch. The length of the shaft and housing will vary according to the need of its application at the specific drilling rig. Some rigs would require a very long .shaft and others only a very short one, so that, for example, the length could vary from six feet to fifteen feet.

Referring now to the form of the invention disclosed in FIGURE 11, 100 designates a conduit through which a fluid, for example, air or other gas, is supplied under appropriate pressure from any suitable source regulated by a cut-ofl valve 101, a portion of which enters communicating branch conduits 102, 103, and 104. The latter conduit 10'4 leads to a normally closed main valve assembly 105 adapted for automatic alternate opening and closing, as required by drilling operations. Conduit 103 communicates with a conduit 106 which directs fluid to said valve assembly 105, which may be a. duplicate of the parts 8, 8a and 8b of FIGURE 1, to open the latter at predetermined pressure. Conduit 103 upstream of its junction with conduit 106 is constricted or reduced at por tion 107, and downstream of that junction has a nozzle 108, throttling release of pressure fluid into the atmosphere.

The rate at which the pressurized fluid is allowed to escape to atmosphere is controlled by. a valve in the form of a flapper 109 whose position accurately. reflects variations in drilling line tension. Said flapper 109 exhibits a degree of sensitivity which is controlled by means of a manually operable calibrating mechanism 110 which is pivoted thereto at 111.

Said flapper 109 is also pivoted at 112 to a conventional Bourdon pressure tube 113.

At this point is to be noted that the parts so far described with respect to FIGURE 11 correspond generally in structure and operation to those designated 2 through 12, 66 and 24a of the form of FIGURE 1.

The conventional rotatable drum 135 for the drill line here designated 136 is mounted within a housing 131. Drilling operation is regulated by the tension of the dead end 114 of the said drilling line or cable 136 at a sensor unit D which is structurally the same as that disclosed in my pending application, Serial No. 836,027, now abandoned, though somewhat differently connected.

More in detail, sensor unit D includes a conventional mounting frame 116 which has an upper spool 121 pivotally mounted at its top at 122 and a spool cam 123 pivotally mounted at 124 adjacent its lower end. An elongated handle 125 extends upwardly from spool cam 123 and the latter, in combination with a dowel means 126 removably positioned within a mating axial recess or recesses of the cam, assists in maintaining the handle 125 and cam 123 in the desired position with the said dead end portion 114 bowed or deflected out of vertical.

Said frame 116 carries a chamber or casing 127 havin, for example, a base wall 150 and an annular marginal wall 151, against the outer free edge of which a flexible diaphragm 117 is suitably fastened as at 152, in spaced parallelism to wall 150 to enclose a space 153. Bolted or otherwise fastened to the diaphragm at 154, and movable therewith, is a plate 155 having a central stud or projection 156 in contact with the bow or deflection of said dead end portion 114. If desired, a plate 157 may also be fastened against the diaphragm by said bolts 154 for further reinforcement.

Projecting centrally from wall 150 is a small housing 118 for a valve 119 slidably mounted in a port 117 in wall 150 which is urged by an expansive coil spring 119" against its seat at said port. A section of the supply conduit 100 at 120 leads to housing 118. A conduit 128 establishes communication between sensor space 153 and the Bourdon tube 113 for expansion and contraction thereof to actual flapper 109 on pivot 111. A continuously open nozzle or drain opening 128' is provided in conduit 128.

A branch conduit 1a supplies power fluid from conduit 1, under control of a valve 1b to a power cylinder 129 pivoted at 129 to wall 131' of the drum housing 131. A piston 130 operates in cylinder 129 to move an alternately applied and retracted power take-off" unit 132 which is suitably slidably mounted on wall 131' at 132 to regulate peripheral contact of a pulley wheel 133 with the inner side surface of one flange 136 of the line spool 135. During the periods of such contact pulley 133 will be rotated and drive a shaft 134 which, through appropriate reduction gearing in the unit 132, drives a flexible or other shafting 138 leading to a planetary gear unit or assembly 139 and connected spool or drum 141 on which [is wound a wire or other string or cable 142 attached to the brake-applying lever 143 of drill line drum 135, the lever 143 being urged toward applied position by a weight 145 and suspending cable 144. i

Said spool 141, for example, may be attached coaxial with and rigidly to the gear ring 11d of a planetary gearing unit or set as in FIGURES and 6 so as to wind and unwind the cable 142 according to the direction of rotation of the drum spool 135.

Said planetary gearing unit is operated by a fluid pressure operated motor 146 when fluid pressure reaches the same through connected branch conduit 1% with the main valve assembly 1G5 open. The shaft of motor 146 and the gear ring 11d may be drivingly interconnected in any suitable manner, as at 49 and 49a in FIGURES 8 and 9.

Presu-ming operation of the mechanism of FIGURE 11, as rock or earth formation is being drilled from under the drilling bit, this causes more weight of the drill pipe to be suspended from the top of the derrick, thus such drilling line cable 136 becomes more taut, therefore increasing pressure at the stud 156 and thus against valve 119, opening it and allowing more pressure fluid to pass spring 119 into chamber 153 behind diaphragm 117. This pressure increase is transmitted through conduit 128 to Bourdon tube 113 which tends to straighten the same and swing flapper valve 109 at point 112, causing the flapper valve to close nozzle 103. Pressure fluid has also been fed into passage 103 through orifice 107, and when nozzle 108 is closed by the flapper valve, this causes a pressure build up in tube 1% onto the diaphragm of the main valve mechanism 105, opening the latter and allowing pressure fluid to pass the valve 105 to and through tube 194 to pressure fluid operable motor 146 to effect the release of brake band mechanism 143 to allow drum spool 135 to release a supply of drilling line 136 which, in turn, lowers the top end of the drill pipe string, placing more weight on the drill bit. At the same time the drum spool 135 starts rotating, which allows friction wheel 133 to drive shaft 134 through reduction gear unit 132, shafting 138, and planetary gear set 139, causing a reverse rotation of the drill line drum spool 135 and causing it to pay out drill line 136, which, in turn, allows weight 145 to apply brake lever mechanism 143 to cause the brake bands of the brake mechanism 143 to halt rotation of drum spool 135 and thus stop paying out of drill line 136 from drum spool; thus effecting a complete cycle of operations. Thus, through linkage of mechanism 143, rotation of drum spool 135 will be braked. With drum spool 135 released, however, the drill bit of drill line 136 will be subject to the weight of pipe or casing applied to the line, causing the drill line to pay out and rotate the drum or spool 141 in the opposite direction. Thus, the control of the instant invention in operation will automatically brake rotation of the drum spool 135 in one direction, or alternately rotate such drum by the drill line cable 136 in the reverse direction. Also, when sufficient weight has been added to the drill bit, depending upon the setting of controller 110, tension of the drill line 136 will decrease which, in turn, decreases pressure on the pressure diaphragm at the projection 1 6 and pressure in chamber 159, which will force the diaphragm 117 away from the valve 119. Bleed-hole 126 will leak constantly to enable said excess pressure to lower the pressure at the dead line diaphragm assembly D corresponding to the tension of the drill line 137. Roller 121, as well as cam device 123425, enables the diaphragm assembly and dead line to be clamped against relative slippage. Branch conduit in, controlled by valve 112, conducts pressure fluid to the cylinder 129 to cause piston 130 to push reduction gear unit 132 toward the adjacent drum spool flange to cause engagement of friction-wheel 133 with said flange.

Although I have disclosed herein the best form of the invention known to :me at this time, I reserve the right to all such modifications and changes as may come Within the scope of the following claims:

What is claimed is:

1. In a system for regulating drill line tension as successively deeper formations are penetrated, drum means mounted to support a supply of said drill line and provided with braking means thereon, means including a line and spool for exerting a variable force on said braking means, a planetary gear assembly mounted to rotate simultaneously with said spool, a first electric motor mounted to supply input torque to said planetary gear assembly to rotate said spool in one direction, a pivotally mounted friction wheel assembly adapted to engage said drum means for simultaneous rotation therewith, mechanism including a second electric motor, hydraulic means driven by said second electric motor, said hydraulic means being adapted to generate fluid pressure to actuate said friction wheel assembly into engagement with said drum, a pressure sensitive switch responsive to said fluid pressure to operatively connect said first electric motor to a source of power, means including a diaphragm tension sensor and Bourdon tube responsive to tension in said drill line to initiate flow of electric power to said first motor, a worm and gear in spaced relation to said planetary gear assembly mounted in operative relationship to said spool, and means connected to said friction Wheel and said worm for imparting input torque to said gear in order to rotate said spool in the opposite direction to increase the force on said braking means.

2. In a system for regulating drill line tension as successively deeper formations are penetrated, drum means mounted to support a supply of said drill line and provided with breaking means thereon, means including a line and spool for exerting a variable force on said braking means, planetary gear assembly mounted to rotate simultaneously with said spool, a first electric motor mounted to supply input torque to said planetary gear assmbly to rotate said spool in one direction, a pivotally mounted friction wheel assembly adapted to engage said drum means for simultaneous rotation therewith, mechanism including a second electric motor, means driven by said second electric motor, said last mentioned means being adapted to generate fluid pressure to actuate said friction Wheel assembly into engagement with said drum, a pressure sensitive switch responsive to said fluid pressure to operatively connect said first electric motor to a source of power, means including a diaphragm tension sensor and Bourbon tube responsive to tension in said drill line to initiate flow of electric power to said first motor, a worm and gear mounted in operative relationship to said spool, and means connected to said friction wheel and said worm for imparting input torque to said gear in order to rotate said spool in the opposite direction to increase the force on said breaking means.

3. In a system for regulating the tension in a drill line according to claim 1, wherein said means connected to said friction wheel and said worm comprises two Selsyn motors electrically interconnected.

4. In a system for regulating the tension in a drill line according to claim 1, in which the means connected to said friction wheel and said worm includes a flexible shaft.

5. In a system for regulating drill line tension as successively deeper formations are penetrated, drum means mounted to support a supply of said drill line and provided with braking means thereon, means including a wire line and spool for exerting a variable force on said braking means, a planetary gear assembly mounted to rotate simultaneously with said spool, a first electric motor mounted to supply input torque to said planetary gear assembly, a pivotally mounted friction wheel assembly adapted to engage said drum means for simultaneous rotation therewith, hydraulic means including a second electric motor and a pump connected to deflect said friction wheel assembly into engagement with said drum, a pressure sensitive switch mounted to sample fluid pressure generated by said hydraulic means, mean-s including a diaphragm tension sensor and Bourdon tube for sampling pressure in said drill line in order to initiate flow of electric power to said first motor responsive thereto and displace said spool to release said braking means and permit rotation of said drum, a Worm and gear assembly mounted in operative relationship to said spool and said planetary gear assembly, and means including Selsyn means mounted to sample rotation of said friction wheel assembly and supply input torque to said worm and gear assembly responsive thereto in order t o reset said braking means and halt rotation of said drum.

6. In a system for regulating drill line tension as successively deeper formations are penetrated, drum means mounted to support a supply of said drill line thereon, braking means mounted to control rotation of said drum, actuating means including a wire line for releasing said braking means and a spool for maintaining a controlled degree of tension therein, planetary gear means mounted to rotate with said spool, a hydraulically operable friction wheel assembly adapted to sense rotation of said drum means, hydraulic circuit means including pump means for supplying pressurized hydraulic fluid to displace said assembly into said rotation sensing relationship with said drum, a pressure operated electrical switch mounted to sample said pressurized fluid and actuate in response thereto, means including a diaphragm sensor and Bourdon tube for sampling tension in said drill line, an electric motor connected to receive power responsive to actuation of said electric switch and said tension in said drill line to drive said planetary gears as well as said spool in a first direction in order to release said braking means, and a Selsyn system connected to sense rotation of said drum and provide an electrical signal responsive thereto including gear means mounted to rotate said spool in a direction opposite to said first direction to reset said braking mechanism.

7. In a system for regulating drill line tension as successively deeper formations are penetrated, drum means mounted to support a supply of said drill line and provided with braking means thereon, means including a wire line and spool for exerting a variable force on said braking means, a planetary gear assembly mounted to rotate simultaneously with said spool, a first electric motor mounted to supply input torque to said planetary gear assembly, a pivotally mounted friction wheel assembly adapted to engage said drum means for simultaneous rotation therewith, mechanism including a second electric motor and hydraulic means having a pump connected to deflect said friction wheel assembly into engagement with said drum, a pressure sensitive switch mounted to sample fluid pressure generated by said hydraulic means and upon actuation thereof to operatively connect said first electric motor to a source of power, means including a diaphragm tension sensor and Bourdon tube for measuring tension in said drill line, switch means connected across a source of electrical potential and actuated by said tension sensor in order to insure flow of electric power to said first motor, a worm and gear assembly mounted in operative relationship to said spool and said planetary gear assembly, and means including a Selsyn system having motors connected to said friction wheel and said worm for imparting input torque to said worm and gear assembly responsive thereto in order to reset said braking means and halt rotation of said drum.

8. In a system for regulating drill line tension as successively deeper formations are penetrated, rotatable drum means including a drum spool mounted to support a supply of said drill line and provided with coacting braking means normally urged to applied position, means including a line and a line spool for controlling said braking means, a planetary gear assembly including differentially movable parts, said line spool being movable with one of said parts, a friction wheel assembly for engaging said drum means for rotation thereby, means for selectively actuating said friction wheel assembly into and out of engagement with said drum means, means including a tension sensor and Bourdon tube responsive to tension in said drill line and another of said parts to rotate the line spool in a direction to decrease the applying force on the braking means, a driving connection for said line spool from still another of said dilferentially movable parts, said last-named part being operatively connected to said friction wheel assembly to allow said line spool to move in the direction to increase the applying force on said braking means.

9. In a well drilling control system provided with a rotatably mounted drum for supporting a supply of the drill line which supports the drill bit, brake means mounted to halt rotation of said drum, rotation sensing means mounted to detect movement of said drum and provide torque responsive thereto, tension sensing means mounted to measure drill line tension and generate a fluid pressure related thereto, fourth means responsive to the generated fluid pressure for rotation in a first direction, fifth means responsive to the provided torque including means for rotation in a direction opposite to said first direction; and spool and line means responsive to rotation in both directions for applying and releasing said brake means, said fourth, fifth and spool means being interconnected by planetary gearing and including gears rotatable on the same axis as said drum, said gears being on opposite sides of said drum.

10. In a well-logging control system for regulating the tension in a drill line during drilling operation, drum means mounted to support a supply of said drill line and provided with friction braking means movable generally transversely of the axis of the drum means, means selectively movable generally axially of the drum means, means responsive to the tension of said drill line for varying the degree of restraint imposed upon said drum means by said braking means, and mechanism including a spool having a line partially wrapped thereon leading therefrom to said braking means, and said mechanism having cooperating planetary movable parts for rotating said spool controlled by said third and fourth means to wind and/ or pay out the last-mentioned line.

11. A well-logging control system according to claim 10 wherein said means movable axially generally of the drum includes a friction element.

References Cited by the Examiner UNITED STATES PATENTS 1,779,581 10/1930 Behnke. 1,779,656 10/1930 Brauer. 1,926,119 9/1933 Smith. 2,117,078 5/1938 Brauer. 2,455,917 12/ 1948 Crake. 2,672,222 3/ 1954 Stevens. 2,759,702 8/ 1956 Abraham. 2,867,411 1/1959 Simmonds et al. 2,931,628 4/1960 Simmonds et al. 2,944,789 7/1960 Le Gate. 2,950,086 8/ 1960 Abraham.

FOREIGN PATENTS 776,132 6/1957 Great Britain.

SAMUEL F. COLEMAN, Primary Examiner.

HARRISON R. MOSELEY, Examiner.

O. M. SIMPSON, Assistant Examiner. 

1. IN A SYSTEM FOR REGULATING DRILL LINE TENSION AS SUCCESSIVELY DEEPER FORMATIONS ARE PENETRATED, DRUM MEANS MOUNTED TO SUPPORT A SUPPLY OF SAID DRILL LINE AND PROVIDED WITH BRAKING MEANS THEREON, MEANS INCLUDING A LINE AND SPOOL FOR EXERTING A VARIABLE FORCE ON SAID BRAKING MEANS, A PLANETARY GEAR ASSEMBLY MOUNTED TO ROTATE SIMULTANEOUSLY WITH SAID SPOOL, A FIRST ELECTRIC MOTOR MOUNTED TO SUPPLY INPUT TORQUE TO SAID PLANETARY GEAR ASSEMBLY TO ROTATE SAID SPOOL IN ONE DIRECTION, A PIVOTALLY MOUNTED FRICTION WHEEL ASSEMBLY ADAPTED TO ENGAGE SAID DRUM MEANS FOR SIMULTANEOUS ROTATION THEREWITH, MECHANISM INCLUDING A SECOND ELECTRIC MOTOR, HYDRAULIC MEANS DRIVEN BY SAID SECOND ELECTRIC MOTOR, SAID HYDRAULIC MEANS BEING ADAPTED TO GENERATE FLUID PRESSURE TO ACTUATE SAID FRICTION WHEEL ASSEMBLY INTO ENGAGEMENT WITH SAID DRUM, A PRESSURE SENSITIVE SWITCH RESPONSIVE TO SAID FLUID PRESSURE TO OPERATIVELY CONNECT SAID FIRST ELECTRIC MOTOR TO A SOURCE OF POWER, MEANS INCLUDING A DIAPHRAGM TENSION SENSOR AND BOURDON TUBE RESPONSIVE TO TENSION IN SAID DRILL LINE TO INITIATE FLOW OF ELECTRIC POWER TO SAID FIRST MOTOR, A WORM AND GEAR IN SPACED RELATION TO SAID PLANE- 